Blasting device.



C. P. ,MoGREGOR.

v BLASTING DEVICE. APPLIOATIQNHLED AUG. 4. 190s.

Patented May 11,v 1909.

www, R NN 11 z wlwllll \\\\\\\\ll||M/l WITN ES'SES y follow from such shots.'

fil filllllli.

' CHARLES ff. MCGREGOILOF PITTSBURG, 'PENNSYLVANIA isLAsfrrNG DEVICE.

Nol 921.144..

Specification-0f Letters Patent.

. p Patented May 11, 1909.

Application alea ziugust 4, 1908. serial No. 446,898.

The obJect of the invention primarily isto prevent blow-outshots in coal mines with lthe disastrous consequences which frequent-ly The invention is applicable inthe'blasting of coal, slate, mineral or otherl strata of earth in any or all kinds of mines, slopes, drifts, shafts,`tunnels, subways, quarries or other excavations. y l VThe invention will be shown and described particularly for use in 'the mining of coal, but it will be understood that itcan be used `whenever blasting is carried on for any vpurpose whatsoever, and allsuch` uses are intended tobe covered by the claims hereinafter made. l l e' The vmain object of theinvention is to remove t-he cause of the: many .explosions and other fatalA and costly accidentsin and around coal mines, due in a great measure,

to the dangerous and tedious methods now Y followed for blasting, the' crude condition or construction of the blasting tools, and the dangerous conditions under which the miner is compelled tol the explosive.

A furtherfobject ofnthe invention .to provide a devic'e`for blasting purposes so arran'ged with reference tothe powder charge or cartridge in the bore hole that the charge will burn and be consumed at a uniformly increasing rate throughout the entire charge to' thereby'genera-te gases in` a ,uniformly increasing-quantity and produce a uniformly accelerating-force. y

I In the accompanying` drawing, Figurel is a side view of my improvedblasting (levice, showing the middle and outer portions charge is obstructed.

-serted `vpowder plug, 3, preferably conical as shown in Fig. l, and provided at its outer end with ln order that the invention and its use, .may be fully understood, l will briefly describe thc usual method of preparing and completing a blast as practiced in an up-to- (late mine in the bituminous coal regions of Pennsylvania. rif he miner first makes a paper cartridge by wrapping the paper around his pick handle; Athen fills the cartridge with powder from a can; then inserts thefilled cartridge into the bore hole and forces it to the rear of the holewith a tamping bar; then inserts the needle into the bore hole and forces the end thereof into the powder of thecartridge then tamps the .hole by filling the saine with damp dirt or slack rand forcing itback with a tamping bar until it reaches the cartridge, holding the needle .with one hand while manipulating the tamping bar with the other'hand, and repeating this operation until the hole is talnped to' the face of the coal, after which he withdrawsthc needle, thus leaving a small hole or passage to the charge of powder which is ignited by means of a patent safety squib which is placed loosely in the hole or passage le'ft by the needle.

Very frequently the blast fails to go off,

which may be due to one of the following reasons: First,damp powder, second, needle not properly placed 1n the cartridge before tamping; third, improper tamping; fourth,

improper withdrawal ofthe needle so that the passage for the squib to the powder In any event the process is a slow and tedious one, as well `as dangerous, due to thefact that 'the miner in fhis anxiety to set ofi' the blast so that he can begin to load the coal, frequently 1 does .not take ,time to do the work properly.

Frequent blow-out shots also occur, and if result therefrom.

My device is intended to greatly facilitate the preparation and completion of a blast and ,also do away with the danger to the Ithe mine is at all gaseous, fatal explosions miner `and especially to prevent blow-out y shots. i

ln ,the drawings the coal or other material to be blasted is indicated at l; 2 indicates the bore hole in which the blast is to be in- The l device comprises a suitable the disk or collar, 4, which serves practically as a closure for the bore hole. This powder 5 ed end, 7, of the bar, 8, which likewise is provided with a squib holel or opening, 9, there through, communicating With the hole in the powder plug. y l

Surrounding the reduced inner end of the io bar, 8, are gripping members comprising Jaws, 10, preferably four in number as shown, which are pivotally mounted on the ring, 11, and are provided with prongs, 12, or saw teeth, 13, or both, for gripping the walls of the bore hole. These grippers are arranged to be ex anded, to engage and grip the walls of the ore hole, by suitable means, that shown comprising a conical s ,eve, 1.5, arranged to be moved inwardly inside of the grippers and expand the latter. This is accomplished by providing the bar, 8, with threads, 16, and correspondingly threading the conical sleeve, l5, internally, so that by rotating these parts relatively to each other,

pand the grippers. The conical sleeve at its outer end is provided with sockets or holes, 17, for receiving projecting portions, 18, on the end of the tube, 19, which surrounds the square, or provided with a hole, 2t), or so that it can be /heldagainst lrotation, and the outer' end of ,the tuba/LQ, is provided with a hole, 2l, for Vreceiving a suitable turning toolV The paiispat their outer end are steadied by means of`a plug, Q2, preferably slightly wedge shaped, ai1d"`--which may be either tubular or formed in several sections, and is inserted iu the outer end of the bore hole around the tube, 1S).

The powder plug, 3, preferably is conical, although it may be straight, and preferably o also is corrugated externally as shown at :253.

Preferably also, a number of perforations, 24:, are ]'irovided, communicating with the squib hole, 5, in said plug. This powder plug is inserted in the cartridge, 25, and proyo jects into the powder, 2G, contained therein.

These cartridges usually are of paper, and the cartridge is secured to the powder plug by wrapping the same willi twine over the corrugations as shown at 27. The end of the cartridge is practically against the Hange or shoulder, 4, on, the powder plug. The device with a cartridge attached is forced into the bore hole until it reaches the end thereof, and the pressure on the bar inwardly causes the paper cartridge to buckle and gatiller, thus forming a packing or plug between the powder plug and the walls of the bore hole. After being so forced in wardly, the bar, 8,- ls held against rotation i, .,id the tube, 19, is rotated, thus rotating the conical sleeve is moved inwardly to exbar, 8, and extends out to the face of the lcoal. The outer end of the bar, 8, is either both,

the conical-sleeve, 15, and moving the saine inwardly between the .frrippers,-10, and expanding the latter and forcing them into the4 walls of the bore hole. Wheirthe grippers are expanded they lie 1n an inclined posa tio`n, as shown in Fig. 3, and hence pressure outwardly causes said grippers to dig into the walls of the bore hole, the pivotal `connection of said grippers allowing them to swing out'to still greater angle as they'enter the coal or rock. 4The greater the pressure the dee )er will the grippers he forced into the coa The consequence'is that when the blast is ignited these grippers prevent the device from moving outwardly and the powder plug and pacliing of paper described absolute y prevent a blow-out or the flame from reaching the face of the coal. In this way blow-out shots are absolutely prevented.

The inner portion, 2l),l of the powder plug, 3, is formed of some iiietal which will not lproduce sparks when it comes into contact with hard foreign substance. Copper is a suitable metal forthis purpose. This prevents accidental ignition of the powder when the blast is being forced into the hole.

Fig. G shows a slightly different form. of powder plug, the same being provided externally with longitudinal ribs, 30, which are practically straight from end to end. The powder plug projects into the powder of the cartridge to a considerable distance, and the flame from the squib ignites the powder at several different places, and as the flame readily travels along4 the face of the pluo', the powder is uniformly burned at an increasing rate, so producing an increasiu'g uniform accelerating forcev against the powder plug, which in turn is transferred to the gril'ipers of the powder plug.

By means of the device described, uniforni. results can always be obtained and with a minimum amount of labor. lt does awa)i with the old slow and tedious method, and also removes the necessity for haste and careless work on the part of the miner, due to the slmvncss of the old method. It not only saves time for the miner, but practically prevents blow-out`sliots or other serious disasters.

lVliat l claim is:

1. A 'blasting device comprising a plug adapted for insertion into the powder or cartridge and provided with an igniting opening therethrough, pivoted expansible grippers associated with, said lug and liaving their outer ends free to swing outwardly and adapted to grip the walls of the borehole, and means for expanding said grippers.

Q. It blasting deviceeomprising a conical plug adapted for insertion into the powder or eartridgeand provided 'with an igniting opening therethrough, pivoted expansible grippers associated with said plug and hav ing their outer ends free to swing outwardly llO ` opening therethrough,

provided with an cartridge and 'provided with an and adapted to 'grip the walls of tlieborehole, and means :for expanding said grippers.

A blasting device comprising a plug adapted for insertion' into the cartridge .and corrugated externally for securing `the cartridge thereto and provided with an igniting opening therethrough, pivoted expansiliaving their outer ends free to swing outwardly, and ineansfor expanding said gripcomprising a plug adapted for inserting into the powder or provided with an igniting opening therethrough, and with perforations communicating with' said opening, expansiblegrippers associated with said plug and having their outerl ends free to swing outwardly, and means for expanding said expanding said grippers and. means for ad vancing said wedge.K

17 A'blastiii'g device comprising a plug igniting opening therethrough, abar' connecting with ysaid plug and opening communicating with'said igniting opcnii-ig, e.\:]` aiisi'blev grip- .i )ers mounted on said bai' and a tub'e sur- Y rou ding said bar and carrying means for l expanding said;l grippers.

'-8*.-.`;`A' blasting device comprising a plug ai'i igniting opening, eXpan-A provided 'with t sible grippers associated with said plug, expanding means for said grippers, anda bar and tube, one-connected to said plug and the other connected to said expanding means and ble' grippers associated with said, plug andA ivoted! v than said corruvations arranged for relative rotation to'expand said grippers. ,l

9. A blasting. evice comprising a plug provided with-'an -igniting opening therethrough, a bar.connected-with said plug and provided with a holecomi'nunicating with said igiiiting opening, expansible grippei's 'associated with saidj lug, a tube surrounding saidv bar, aconicalJ wedge/ for expanding the grippers and having a threaded-engagement with said bar, and means for producing relative rotation between said bar and tube toadv'ance said conicalwedge.

l0. A blasting device comprising -a plug .provided with an igniting opening therethrough, said lug, a bar connected 'to said plug and provided with a hole communicating with vthe igiiiting'opening in theplug, a tube sui'- rounding the bar and carrying panding the grippers, around tlie outer end of ing the tube and bar.

11. A blasting device, comprising a conical plugadapted for insertion into the cartridge and provided with anigniting opening thereineans for exa-nd a sleeved plug through, a'collar or disk at the base of the Y conical portion of the plug. and of larger diameter than said base and forming a packing abutment for the cartridge, enpansible grippers associatedwith said plug and means for expanding said grippers.

l2, .A'blasting device, comprising a conical plug provided with an ignitingopening there through and corrugated externally to provide 'means for-the attachment' of the cartridge-thereto, a collar or disk on the outer end' of. said plug and of larger diameter and forming a packing abutment fir the cartridge, expansible grippers associated with said plug, and means for expanding said grippers.

, In testimony whereof, I have hereunto set my hand.

CHARLEs r. MCGREGQR.

Witnesses:

` JOHN S. Coii'r,

yF, W.W1NTER.

exp'ansible grippersl associated withsaid tube for steady; 

